Powershift transmission
A powershift transmission is a special form of vehicle transmission in which the ratio can be changed under load, i.e. while driving, without interrupting the torque . This means that propulsive forces can also be transmitted during the shifting process, the vehicle can continue to accelerate during the shifting process, so there is no loss of comfort during the shifting process.
When shifting a gear, a shift element of the old gear is opened and another shift element of the new gear is closed at the same time. Group shifts with more than two shift elements involved are generally avoided, but cannot be bypassed in tractor transmissions due to the group design.
As a rule, the shifting elements are designed as friction clutches (mostly multi-plate clutches ), and more rarely, hydrodynamic clutches that can be filled and drained are used.
Conventional automatic transmissions in passenger cars are powershift transmissions, and dual clutch transmissions also enable gear changes without interruption of tractive power.
tractor
For tractors power shift are also used because they allow for faster work especially when working in hilly terrain and on varying soil types and help to save fuel. Tractor transmissions can often only be partially shifted, which means that it is only possible to shift between some gears without an interruption in tractive power, while others (e.g. group change) are associated with an interruption in tractive power.
In 1962, the Massey Ferguson Multi-Power Transmission was the first in the industry to allow gear changes while driving. It was offered as an option on select Massey Ferguson tractors. It was possible to change gears between “Low” and “High” from each gear and from each group. The standard transmission with six forward and two reverse gears became 12 forward and four reverse gears.
See also
Individual evidence
- ^ History of Massey Ferguson 1960s ( Memento of the original from November 29, 2010 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
